package com.edu.service;

import com.edu.entity.User;
import java.util.List;

public interface UserService {
    User register(User user);
    User login(String username, String password);
    User findById(Integer userId);
    List<User> findAll();
    User update(User user);
    void delete(Integer userId);
    boolean checkUsernameExists(String username);
    void changePassword(Integer userId, String newPassword);
}